Washington (CNN): The first CNN/ORC poll of likely Democratic caucus-goers in Iowa finds Hillary Clinton firmly in the lead in the state that kicks off the nation’s nominating contests, holding a 50% to 31% lead over upstart Vermont Senator Bernie Sanders. Vice President Joe Biden, who has yet to decide whether to make a run for presidency, lands in third place with 12%, with the rest of the field at 1% or less.

The slightly-tighter-than-national race reflects two broad divides among Iowa’s Democratic voters: a gender gap and an ideological split. Among women, Clinton tops Sanders by more than 30 points, 58% to 26%. Among men, the two are even: 38% back Clinton, 37% Sanders. Likewise, among the party’s moderates, 57% back Clinton, 21% Sanders, while liberals split 46% for Clinton to 41% for Sanders. And liberals are most apt to say they are firm in their choice: Fully 42% say they’ve definitely decided whom to support, compared with 30% overall.